Objective To investigate the changes of proteomics in serum of Sprague-Dawley(SD) rats after accumulated irradiation with 137Cs γ-rays.Methods A total of thirty mature SD rats were randomly divided into three groups:0.2 Gy group,2 Gy group and healthy control group.Rats were irradiated at a dose rate of 0.336 mGy/min for 10 d and 20 d continuously.Isobaric tags for relative and absolute quantitation (iTRAQ) was used to analyze the different protein expression in serum of irradiated rats.Gene Ontology,KEGG pathway and protein-protein interaction network analysis were conducted using softwares.Results In total,363 protein spots were identified.Twenty nine proteins were differentially expressed in both groups compared with control,of which 10 proteins were up-regulated and 19 proteins were down-regulated.Based on the information of GO categories,these differentially expressed proteins were mainly located in the cytoplasm and membrane concerning the function of binding and catalytic activity.Analysis with the PAJEK software demonstrated that 16 differentially expressed proteins could form a complicated interaction network where glutathione S-transferase P1 (GSTP1),phosphoglycerate kinase 1 (PGK1) and protein disulfide-isomerase (PDI) might be key nodes.Conclusions Accumulated irradiation can induce differentially expressed proteins in serum of irradiated rats.Analysis on functional roles of the screened proteins GSTP1,PGK1 and PDI may provide insight into further mechanistic investigations and underlying molecular biomarkers induced by accumulated irradiation.

Objective To explore the effects of accumulated 60CD,γ-ray irradiation on small molecular metabolites in rats urine.Methods Ten healthy male SD rats were irradiated by 60Co γ-rays in 5 days and the accumulated doses were 0,0.2,0.4,0.6,0.8,1.0 Gy,respectively.The metabolites in urine of different groups were measured with 1 H-NMR combined with principal components analysis (PCA) and partial least square discriminate analysis (PLS-DA). Results The metabolites in rat urine were obviously changed after irradiation. Compared with control group,the amount of acetoacetate decreased after irradiation(t =29.7 -30.7,P ＜ 0.05 ),but its relative level was stable when the dose increased ( P ＞ 0.05 ).Meanwhile,the relative level of hippuric acid increased ( t =4.4 - 21.6,P ＜ 0.05 ) especially when the accumulated dose was higher than 1 Gy (t =21.6,P＜0.05). The relative level of proline,taurine and trimethylamine-N-oxide increased after irradiation with the same trend( t =3.5 - 13.4,4.7 - 11.5,2.9- 12.7,P＜0.05). Conclusions The acetoacetate,hippuric acid,proline,taurine,and trimethylamine-N-oxide may be applicable for biomarkers of accumulative irradiation on rat.

OBJECTIVE: To compare the effects of ~(56)Fe~(17+),~(12)C~(6+)ion beams and~(60)Co γ rays on chromosome aberration in human lymphoblastoid cells. METHODS: The human lymphoblastoid cells were divided into 0. 1,0. 3,0. 5,0. 7,1. 0,2. 0 Gy irradiated groups and 0. 0 Gy control group. They were separately exposed to ~(56)Fe~(17+)ion beams( linear energy transfer was 400. 0 ke V/μm),~(12)C~(6+)ion beams( linear energy transfer was 26. 0 ke V/μm) and~(60)C γ rays. Chromosome specimens were harvested 48 hours after irradiation. The effects of different radiation on dicentric plus centric ring( “d + r”) aberration rate and chromosome aberration in human lymphoblastoid cells were detected by light microscope with artificial counting. RESULTS: The “d + r”aberration rates induced by 0. 3-2. 0 Gy ~(12)C~(6+)ion beams were significantly higher than those of ~(56)Fe~(17+)ion beams and~(60)Co γ rays at the same dose( P < 0. 017). Chromosome aberration cell rates of 0. 1-2. 0 Gy ~(12)C~(6+)ion beams were significantly higher than those of ~(56)Fe~(17+)ion beams and~(60)C γ rays at the same dose( P < 0. 017). At the dose range of 0. 0-2. 0 Gy,chromosome aberration effects of three kinds of radiations were gradually increased( P < 0. 01). The relative biological effectiveness of ~(56)Fe~(17+)ion beams was lower than that of ~(12)C~(6+)ion beams.CONCLUSION: The chromosome aberration induced by ~(12)C~(6+)ion beams was more serious than that of~(60)Co γ rays and ~(56)Fe~(17+)ion beams.